P0A11 and how not to get scammed by mechanic

1. How many miles are on the vehicle?
2. How many hours per week are you driving?
3. When was the last time the 12v battery was changed? (there should be a date code on the top)
4. Why do you think you have to take her in, what "code came up" ?
5. If you did take her in, where would that be? (dealership, hybrid shop, etc.)
6. Do you have some tools and a DIY attitude, or will you be paying to make problems go away?

FYI - your postings are moderated until you've posted five (5) times.

 

Step one is to determine if this P0A11 code is legitimate.

How did you acquire the code? If you DIY'd it, what code reader did you use? There are many available that DO NOT read Prius codes correctly. Put simply, they don't speaking Toyota 'hybrid language'. Many people have chased their tails trying to resolve an issue that doesn't actually exist. Let's make sure we know what the true problem is, before we start down a troubleshooting path.

A quick look in the repair manual and I don't even see a P0A11.

 

You killed the 12 from not driving it much and the expensive hybrid battery will fail next.

Replace the 12 battery, go to Batteries+. and buy there SB version battery for the g2 battery fits the battery hole has 4 year warranty and $224.

there is literally thousands of 12 volt posts on this site use search link up top and search guess what:

12 volt battery

If your going to the dealer and paying them for diagnostic codes get it in writing next time.

 

Given 4-6, it would be best if you procured a 'mini-vci' cable (20 usd) and found out the extent of the problem at hand.

Sounds like it would still be under warranty, best to let the seller bench test it and replace as needed. You may need to disconnect the 12v until you've sorted out the issue(s). Do you have or are you currently using the SKS feature?

Many DIY'ers prefer to use a 'mini-vci' cable (20 usd) and techstream (dealer technician software) installed on a windows device. Others will get by with an App like Dr Prius or Hybrid Assistant on a OBD2 bluetooth adapter.

If I were to make a WAG on DTC P0A11 for this application, it might be a P0AA6 (aka P3009), and has associated subcodes (INFs)

 

There are 2 cables connecting to the 12 volt battery. One is a thicker black wire one is a thinner black wire. The thick one is the main power cable from the battery to the front jump point in the fuse box the thinner is the Inverter sensing wire for the dc to dc converter. make sure that wire is plugged into the positive terminal assy.

Then Check to see if the dc converter is working. Put the car in ready and measure at the front jump point with a dvm it should be around 14 charging volts.

 

Please review this thread. OP was getting same code, then later used Techstream and received a very different code.
P0A11 code | PriusChat

That doesn't necessarily mean you may get the same 'other code'.

Here are the Hybrid Code sheets for HV Control and HV Battery. After looking through the repair manual in a bit more detail, I still see NO P0A11 code listed anywhere.

 

A much better first step is to determine if the 12 V battery is really bad or not and replace it if necessary.

[Edit:] I see it has been replaced already. See my other reply.

 

Many new batteries come with a 50% charge or less; basically dead on arrival.
Did you manually charge the new one before use ??
Even shops who should know better often don't do that.

Also the charging voltage should be checked after installation.

 

Did this problem ever get solved?